498 PROCEEDINGS OP THE GEOLOGICAL SOCIETY. [May 23, 



inch 10 lines ; greatest breadth of abdomen 1 inch 1 line ; length of 

 carapace 1 inch 7 lines ; length of abdomen 1 inch 10 lines ; length 

 of telson 7 lines ; length of forearm and hand 15 lines ; breadth of 

 hand 4 lines. 



4. Eeton Wilmcotensis, spec. nov. PI. XXIV. fig. 3. 



A slab from the collection of Charles Moore, Esq., E.G.S., of Bath, 

 contains no fewer than fifteen individuals of a small species* of Eryon, 

 which I have been extremely unwilling to treat as distinct from E. 

 Barrovensis, on account of the circumstance that the entire group are 

 preserved with their ventral surfaces exposed, and in none can the 

 contour of the carapace be traced. 



Among the specimens from the collection of R. F. Tomes, Esq., 

 F.Z.S., is a small carapace without any appendages, which, how- 

 ever, agrees very well in size with the above-mentioned examples, 

 and may, perhaps, be identical with them. 



The former is from the railway-cutting at Pyle TTill, near Bristol, 

 from the " insect-bed " or " Modiola-minima " bed of the geological 

 surveyors, one of the basement beds of the Lower Lias. 



The latter is from Wilmcote, near Stratford- on- Avon, from the 

 " bottom block "-bed of the Lower Lias. 



This carapace (see figure) is somewhat shorter and broader in its 

 proportions than E. Barrovensis (measuring 14| lines in breadth, 

 12 lines in length) ; the branchial region is more rounded ; and the 

 dentations around the margin of the carapace are much wider in 

 proportion to its size ; whilst the relative distance across the frontal 

 portion is twice that of E. Barrovensis. The surface of the carapace 

 is evenly covered with minute granulations ; and there are no large 

 tubercles along the median line, such as occur in the former species. 



Whether the Pyle-Hill specimens be identical with the Wilmcote 

 example remains to be proven ; in the meantime I have ventured to 

 name the carapace Wilmcotensis, as I think it important to draw 

 the attention of Liassic palaeontologists to this subject, in the hope 

 that more complete specimens may be sought for. 



5. Erton Brodiei, spec.nov.t PI. XXIY. fig. 2. 



This unique form is from the Lower Lias rock, Lyme Eegis, and 

 is at once distinguishable from the other species of this genus by its 

 more strongly ridged carapace and the straightness of the margin 

 along its branchial regions ; the greatest width of the carapace is not 

 in the centre of the branchial portion, but at its extreme front, from 

 which point the breadth decreases to one-third at the posterior mar- 

 gin, which, however, is mutilated. The hepatic region is less dilated 

 laterally, but wider in front than in E. Barrovensis ; and the orbital 

 foss88 and rostral indentation are less deep. In this specimen one 

 eye is preserved in situ. A second furrow (but faintly seen in the 

 centre of other species of Ei^yon) crosses the entire breadth of the 



* Measuring 2 inches in their greatest length, and about f inch in width, 

 t British Museum Collection. 



